Antibiotic-Impregnated Valve Body: Defit Shunts Explained
Valve-body impregnation in Defit shunts explained: what is impregnated, which sizes and codes carry it, and how it differs from impregnated catheters.
Valve-body impregnation means the antibiotic is impregnated into the material of the Defit silicone valve body and released in a controlled manner over 28 days. Every Defit size and pressure is available this way as a valve alone (ADFUS, ADFS and ADFR codes). Regular-size full-antibiotic kits have it too, and their catheters are impregnated as well.
Key takeaways
- In valve-body impregnation the antibiotic is in the material of the valve body and is released in a controlled manner over 28 days.
- Every Defit size and pressure is available with an impregnated valve body as a valve alone: ADFUS, ADFS and ADFR.
- The only Defit kits with an impregnated valve are the Regular full-antibiotic kits, whose catheters are impregnated too.
- The orange colour rule applies to catheters, so identify an impregnated valve by its code, not its appearance.
Most discussion of antibiotic-impregnated catheters is about the catheters, but Defit shunts offer the same impregnation in the valve body. The choice of configuration belongs to the surgeon and the hospital’s protocol, following the instructions for use. To compare semi and full kits across all three DESU families, see semi-antibiotic vs full-antibiotic shunt kits.
What does valve-body impregnation mean?
Impregnated means the agent is held in the material itself, not in a layer on its surface. The Defit valve has a flat-bottom silicone body, so in the impregnated versions that body carries the antibiotic. The release is the same as in DESU impregnated catheters: controlled, from the material, over 28 days. For more on what the period means, see the 28-day release explained.
“Valve-body-only” is our term for the option in which the valve is impregnated and no impregnated catheters are involved. It is one of three antibiotic options for Defit, alongside semi-antibiotic and full-antibiotic kits.
Which parts are impregnated in each Defit option?
| Option | Valve body | Catheters | Example code |
|---|---|---|---|
| Standard valve | Standard | None supplied | DFS-M |
| Valve-body-only | Impregnated | None supplied | ADFS-M |
| Standard VP kit | Standard | Standard | DFS-M-VCK |
| Semi-antibiotic kit | Standard | Impregnated | DFS-M-VACK |
| Full-antibiotic kit | Impregnated | Impregnated | ADFR-M-VACK |
Read it one column at a time. Semi-antibiotic and full-antibiotic kits have the same impregnated catheters and differ in the valve body. Valve-body-only and full-antibiotic share an impregnated valve body and differ in whether catheters are part of the order.
Which Defit sizes and pressures are available?
All three Defit sizes are available with an impregnated valve body, each in low, medium and high fixed pressure. The leading “A” in the code marks the impregnated version.
| Model | Overall length | Body length | Thickness | Impregnated valve codes |
|---|---|---|---|---|
| Ultra Small | 35 mm | 20 mm | 4.5 mm | ADFUS-L, ADFUS-M, ADFUS-H |
| Small | 40 mm | 25 mm | 5.5 mm | ADFS-L, ADFS-M, ADFS-H |
| Regular | 45 mm | 30 mm | 7 mm | ADFR-L, ADFR-M, ADFR-H |
How does size affect the kit options?
This is the detail most easily missed. Which kits you can order with impregnated catheters depends on valve size:
- Regular: full-antibiotic kits, ADFR-L-VACK, ADFR-M-VACK and ADFR-H-VACK, also with an antisiphon device, as in ADFR-M-VACK-ASD.
- Small: semi-antibiotic kits, with a standard valve, such as DFS-M-VACK.
- Ultra Small: kits with standard catheters, such as DFUS-M-VCK.
So an impregnated valve in Ultra Small or Small size comes as a valve alone, and no Defit code pairs an impregnated valve with standard catheters. If a surgeon’s request falls between these options, tell us before assuming a code exists.
What stays the same in an impregnated Defit valve?
These Defit properties hold across the family, impregnated versions included:
- Flat-bottom silicone body with no metal parts, suitable for MRI and CT.
- Low, medium and high fixed-pressure options.
- Single-use supply, sterilised by ethylene oxide.
- CE marking and manufacture under ISO 13485.
How does a valve-body option differ from impregnated catheters?
The difference is where the antibiotic sits and what comes in the box. Catheters run from the ventricle to the valve and from the valve to the peritoneal cavity; the valve sits between them. An impregnated valve is one component of that pathway. Impregnated catheters are the two components either side of it.
There is also a practical difference. An impregnated valve ordered alone arrives without catheters, so they are ordered separately. One route is the ventriculoperitoneal catheter kit, coded SVPCK in its standard version and ASVPCK in its impregnated version. Which pairing suits a patient is a surgical decision.
How can you identify an impregnated valve?
Do not rely on colour. DESU impregnated catheters are orange and standard ones white, but that rule applies to catheters only. A valve ordered alone has no catheter beside it to give a visual cue.
The code is the reliable check. ADFS-M is a valve with an impregnated body. DFS-M-VACK also contains the word “antibiotic” in its description, yet its valve body is standard. Both can fairly be called antibiotic products, and they are different things, so an order should never rest on the word alone.
On the order and on receipt, check:
- That the code begins with “A” if an impregnated valve body is intended.
- That size and pressure letters match the request.
- That catheters are ordered separately if the code has no package letters.
- That the label on arrival matches the order line in full.
Do other DESU shunt families offer it?
Yes, under their own codes. Decurve offers impregnated valves in paediatric and adult sizes (for example ADCP-M and ADCA-M) and full-antibiotic kits (ADCP-M-VACK, ADCA-M-VACK). Adjustable Depus valves have an impregnated-body version in paediatric and adult sizes (ADP-A and ADPA-A), including kits with standard catheters such as ADP-A-VCK.
Talk to a DESU product specialist
For Defit codes, documentation or help matching a surgeon’s request to a configuration, write to sales@desu.tr, use the contact page, or request a quote.
Frequently asked questions
Does an impregnated valve body change the pressure options?
No. Low, medium and high pressure versions are available in each of the three sizes, as with the standard valves.
Can I order a Small kit with an impregnated valve body?
The Small kits have a standard valve, with standard or impregnated catheters. The Small impregnated valve comes on its own. Tell us if your department needs something else.
Is a valve-body option a substitute for impregnated catheters?
They are different configurations, and we do not rank them. Which components should be impregnated is a decision for the surgeon and the hospital’s protocol.
Does valve-body impregnation reduce infection?
We make no outcome claim for valve-body impregnation, and the choice of configuration is the surgeon’s.
Related standards
- ISO 7197: Neurosurgical implants — Sterile, single-use hydrocephalus shunts and components
- ISO 11135: Sterilization of health-care products — Ethylene oxide
- ISO 13485: Medical devices — Quality management systems